The Rock Ventures proposal to develop the site at the unfinished Wayne County jail in downtown Detroit along with building a new criminal justice complex would create $2.39 billion in economic impact for southeast Michigan and add 2,106 permanent jobs, according to a report prepared for the company and released Tuesday.

Rock Ventures is proposing to build a $1 billion mixed-use development anchored by a 23,000-seat Major League Soccer stadium and a high-end residence and hotel on the 15-acre site of the unfinished Wayne County jail on Gratiot near Greektown.

Rock Ventures has proposed that in exchange for the jail site, the company also would build a Criminal Justice Center that would include a 1,600-bed jail, a juvenile detention facility and courtrooms. The center would be built north of downtown on an eight-acre site just east of the Interstate 75 service drive between East Forest and East Warren.

But ever since announcing the plan last year, county officials have been cool to the idea that would have to be approved by the Wayne County Commission and County Executive Warrren Evans.

Evans on Tuesday called the new study “irrelevant.”

The economic impact study, prepared by the Center for Sport & Policy at the University of Michigan and commissioned by Rock Ventures, also noted that the total economic impact of completing the jail site is estimated at $352 million, or more than $2 billion less than the impact of Rock Ventures’ proposal, according to the study.

Wayne County officials have said they would likely decide in May whether to accept Rock Ventures proposal or finish building the jail.

“The contrast between the impact of the two options before the county is striking: The county can finish the current Gratiot site jail, creating minimal economic impact, produce no increase in permanent jobs and generate zero future property tax or additional city and state income tax for the next several decades,” said Rock Ventures founder and chairman Dan Gilbert in a prepared statement.

Evans said the “study does nothing to sway my thinking” because it fails to answer the county’s concern of whether Gilbert’s proposal would further delay getting a new jail.

In the written statement, Evans added: “My standard for Rock’s proposal has been absolutely clear: Is Rock prepared to build the county a criminal justice complex in a timely fashion, with buildings that meet our needs, at a price Wayne County can afford? If they can’t meet that standard, everything else is irrelevant. This study moves us no closer to answering that fundamental question.

“If the benefits of one project over another are so overwhelming, it’s on those who stand to gain from it to create an alternative option to Gratiot that best protects Wayne County taxpayers. And they need to do it with the urgency and focus that takes into account the impact this project has already had on our residents, just six months removed from a consent agreement necessitated by a deep fiscal crisis.”

The jail project on Gratiot was halted in June 2013 when cost overruns pushed the price tag from $220 million to an estimated $391 million and led to corruption charges against two Wayne County officials and one contractor about the cost overruns.

The complex, on a 15.5-acre site near Interstate 375, was designed to consolidate Wayne County’s criminal justice facilities downtown. Construction on the site — bounded by Gratiot, the Chrysler Service Drive, Macomb and Beaubien — began in 2011.